I've been submitting my songs to music libraries, I have already registered them through BMI. Some of the libraries who have accepted my songs are asking for the instrumental version of the songs. My question is.... naming the instrumental version. Lets say the song title is "Love You Baby" Would you call it and register it as "Love You Baby Instrumental" ? Can you register it as a totally different name?
What do most people do? are there any pro or cons either way? Thanks in advance!!

The best bet is to not register anything at all. Let the publisher / library do that for you. It's part of their job anyway, and you won't run the risk of screwing anything up! Unless they specifically tell you to register them yourself (very unlikely, although it does happen), just let them do it.